The billionaire, 41-year-old Xu Ming, is the founder and chairman of the Dalian Shide Group, a conglomerate whose holdings range from home appliances to finance to building materials. Mr. Xu failed to appear as scheduled on Monday at the Bo’ao Forum for Asia, an annual gathering of leaders from business, government and academia on Hainan Island in southern China.
Economy and Nation Weekly, a financial magazine affiliated with the state-run Xinhua news agency, quoted unnamed sources on Saturday as saying that Mr. Xu had been put under the control of Communist Party investigators in connection with “economic cases,” a term often associated with corruption. Major news outlets carried similar reports over the weekend, but government censors have deleted Internet references to the case.
It was unclear whether any inquiry might involve Mr. Bo, a national power broker who was removed as party secretary of metropolitan Chongqing on March 15.
Since then, investigators with the party’s Central Commission for Discipline Inspection have summoned a number of officials and individuals tied to Mr. Bo, 62, for interrogation in Beijing. The commission has been quietly looking into Mr. Bo and his underlings since last year or earlier. But that inquiry has clearly intensified in the two weeks since his dismissal as Chongqing’s party chief, according to Chongqing officials and businessmen who spoke on the condition of anonymity for fear of repercussions.
Mr. Xu has not been in contact with the Shide Group since March 14, the day before Mr. Bo was fired, the Internet service Sina Finance News reported. Contacted over the weekend by telephone, officials in Dalian and in Liaoning Province, as well as the disciplinary commission and the public security ministry, all said they had no information about Mr. Xu.
Even in ordinary times, an investigation of Mr. Xu, whose fortune has been estimated by Forbes magazine at $690 million, would draw national attention. But the latest report took on added importance as a potential indicator of efforts by the ruling elite to build a case against Mr. Bo in advance of a turnover in the party’s leadership late this year.
Mr. Bo, who sits on the Politburo, had campaigned to join the body’s Standing Committee, the group that effectively runs China.
David Barboza contributed reporting from Shanghai, Jonathan Ansfield from Beijing, and Jane Perlez from Bo’ao, China.
A version of this article appeared in print on April 3, 2012, on page A6 of the New York edition with the headline: Chinese Investigate Titan Linked to Toppled Official.